Answer: 
<u>Step-by-step explanation:</u>
Given: cos x =
, x is in Quadrant 4
Use Pythagorean Theorem to find sin x:
8² + y² = 17²
y² = 17² - 8²
y² = 289 - 64
y² = 225
y = 15
→ sin x = 
Use the double angle formula to find cos (2x):

Answer:
x=4
y=7
Step-by-step explanation:
12=3x
x=4
6=y-1
y=6+1
y=7
Answer:
16
Step-by-step explanation:
Answer:
180’ - 130’
Step-by-step explanation:
Answer:
30% Probability
Step-by-step explanation: 3/10=0.3